Well, I operated the 737-200 in a previous life and a few of the Captains used to cut both engines as we approached the stand. One day we did this and the brakes then failed. As we gently rolled towards the bowser the Captain opened his DV window and yelled at the marshallers to throw a chock under the nosewheel. Eventually they caught on and the a/c stopped dead about 4' away from the bowser, accompanied by the sound of 189 passengers falling over and all the catering falling out of the galleys.
So I don't think it's safe............